The causes of distortion in Line scan camera
Line scan camera are widely used in today's industrial production, and their excellent performance has been widely recognized. However, everything has advantages and disadvantages. When using a line scan camera, we may encounter a problem, which is line scan camera distortion. So, what exactly is the cause of distortion in Line scan cameras? This article will elaborate on the following aspects.
1、Principles of Optical Imaging
A Line scan camera is a camera based on optical imaging principles, which focuses the light reflected by an object onto a photosensitive element through the lens,forming an image. Distortion refers to the phenomenon where the shape and size of an image do not match the actual object. The occurrence of this phenomenon is mainly due to two defects in optical imaging principles: radial distortion and tangential distortion.
1. Radial distortion: When light passes through a convex lens,due to the shape limitation of the convex lens, the light will deflect in the part passing through the center of the lens. This kind of deflection will cause the central part of the object in the image to be larger than the actual object, while the edge part will be smaller than the actual object. This is the manifestation of radial distortion.
2. Tangential distortion: When light passes through an aspherical lens,due to the shape limitation of the aspherical surface, the light will bend at the edge of the lens. This kind of bending will cause the edge part of the object in the image to be larger than the actual object, while the center part will be smaller than the actual object. This is the manifestation of tangential distortion.
2、The structural characteristics of linear array cameras
The structure of a Line scan camera mainly includes photosensitive components,lenses, and shutter components.Due to certain errors in the design and manufacturing process, these components are prone to distortion during use.
1.Sensor: Sensor is the core component of a Line scan camera, which determines the quality and clarity of the image. However, due to the continuous reception and processing of light by photosensitive elements during operation, there may also be certain errors within them, leading to image distortion.
2.Lens: The lens is a bridge connecting photosensitive components and imaging systems, and its focusing effect on light directly affects the quality of the image. However, due to errors in the design and manufacturing process, as well as wear and tear during use, lenses often produce radial and tangential distortions.
3.Shutter: Shutter is a key component that controls exposure time, and its control of light directly affects the clarity and brightness of the image. However, due to the presence of a shutter, there may be a certain degree of flicker in the image during the shooting process, resulting in image distortion.
To avoid the occurrence of distortion in Line scan camera, we need to start from the following aspects:
1. Optimize optical system design: By optimizing components such as lenses and filters, reduce the impact of radial and tangential distortions;
2. Improve the performance of photosensitive components: By improving the structure and materials of photosensitive components,their sensitivity to light and capturing ability can be enhanced;
3. Adopting digital correction technology: correcting the captured images through image processing software to eliminate the effects of radial and tangential distortions;
4. Using multiple image overlay technology: By overlaying multiple images, it is possible to effectively correct orthodontic phenomena.